Questions tagged [functions]
Questions about the use of built-in Mathematica functions, including pure functions.
3,148
questions
-3
votes
0answers
47 views
How to create a global function? [closed]
I am wondering how to create a global function.
I want to build a function that will persist even when Mathematica's kernel is aborted and closed and eventually restarted. I think the answer has ...
0
votes
0answers
54 views
How to sort functions based on the number of arguments they take? [closed]
How can I find all functions with a certain number of arguments?
For example, how can I find all the functions who do not require an argument like RandomReal[]?
How can I find all the function that ...
0
votes
0answers
48 views
how to find the FWHM of a peak from an equation and not data set? [closed]
I want to find the FWHM of a conductance peak I created on mathematica (see Figure). until now I used the FindMaximum to calculate the max of the peak.
...
0
votes
0answers
43 views
How to get a list of all the Resource Functions on the Wolfram Function Repository? [duplicate]
I would like to find a way to get the name of every single ResourceFunction published on the Wolfram Function Repository. How can I find the names of every single function?
0
votes
1answer
36 views
How to define a matrix of functions that taking given letters as variable without giving specific expressions? [closed]
I have a vector defined by coord = {r, \[Theta], \[Phi], t}. Now I want to create a matrix of functions taking these $r,\theta,\phi,t$ as variables without giving ...
3
votes
1answer
86 views
What is the difference between Catenate and Flatten? [closed]
I am having a hard time understanding the difference between Flatten and Catenate.
Consider the following example code:
...
0
votes
1answer
77 views
Solving a system of coupled trigonometric equations to find angles
I have a system of 9 coupled trigonometric equations (a 3X3 Matrix). I am trying to find four unknown angles $\theta_1, \theta_2, \phi_1, \phi_2$ by solving any 4 out of 9 such equations.
$\text{M}=\...
2
votes
2answers
186 views
Defining a function recursively
I want to construct polynomials (or just function) $f_n$ from $f_{n-1}$ using mathematica. For some kind of reason, I didn't manage to do this. So basically something like a recurrence table, but for ...
2
votes
2answers
80 views
Problems with TagSet
I am new with TagSet and TagSetDelayed and I'm not understanding properly how they works. I introduced the following definition:
...
1
vote
2answers
63 views
Why the animation of a function gives different results from the integral?
My function is:
A1[B_, x_, t_] := (AiryAi[B*(x - (B^3*t^2)/4)])^2
(B is a constant) and if I use "Manipulate" :
...
2
votes
2answers
51 views
Partially Orderless Arguments in Functions
I am a Mathematica beginner and I'm trying to implement a function of type
f[i1_,i2_,i3_,i4_]
such that it is orderless in the first two arguments and in the last ...
0
votes
1answer
57 views
NBodySimulation softening parameter
I'm simulating the orbit of a binary black hole immersed in some halo of particles and the simulation does not want to continue on for the specified amount of time. It always halts at a seemingly ...
0
votes
1answer
56 views
How to find all functions that accept level specifications as an argument?
How can I find a list of every function that takes a level specification as an argument?
0
votes
1answer
43 views
Integrate and InverseFunction
I solve an easy example to check that Mathematica can understand the difference between ArcTan and ArcTanh but as you see here I can't get Arctanh??!! Even I don't know why the inverse function is not ...
1
vote
0answers
47 views
Loops Not Working- Kernel Crashes and Values Incorrectly Updated
I haven't used Mathematica in a while so any help is very greatly appreciated.
I am trying to run a program with nested for loops that runs two function evaluations in the inner most part of the loops....
0
votes
1answer
31 views
I have a variable error and was curious to see if it's due to piecewise functions?
So I have a displacement function sigx as a function of "t" (time) and sig.pre (pre-stress). At some time "dx": force "fo" goes to 0, and the same displacement function ...
2
votes
1answer
109 views
Biot-Savart Integral
I want to calculate the magnetic field of a finite wire of current along the z axis. I assume a frame of reference like the one in Fig. below:
It is a classical problem with a well known solution for ...
1
vote
1answer
37 views
Simplify function with condition not working [duplicate]
I try to simplify the function Q below:
Q[x_] := Sign[x] /; x > 1
Simplify[Q[x], Assumptions -> x > 1]
(*return Q[x]*)
But it doesn't work. However, if I ...
2
votes
2answers
79 views
Calculation of composite integrals
I am facing trouble calulating the following integrals. Could you give me any advice?
My code is the following:
...
0
votes
0answers
42 views
Silly trouble expressing recursive formulas?
I am trying to code the following formulas:
I did it in the following way:
...
0
votes
0answers
40 views
NIntegrate seems to not recognize multiplication of Piecewise function and f[t_]:= function, Why?
Considering inputs:
vti={0, 1.5, 2.4, 5.0675, 7.735, 10};
Vscc=1.5; PSA=0.025; f=0.6; m=10;
I defined a function "pwtemp2", using "FC1" and &...
4
votes
2answers
309 views
Mean of boolean list
In python I'm used to doing something like np.mean([True, False, True......]) to compute the fraction of True values in a list. ...
0
votes
1answer
98 views
Matching a Dynamic Argument Pattern
times is a list of times i.e. matching {{hour_, min_, sec_Real}..}.
I want to call ...
1
vote
1answer
99 views
0
votes
0answers
22 views
Adaptation of existing code to multivariable system
I am trying to adapt the existing code from "Mathematica package for analysis and control of chaos in nonlinear system" by Gutierrez. This existing code calculates the Lyapunov Exponent by ...
1
vote
0answers
60 views
Big O notation - Strange result [closed]
I tried to use the big O function in Mathematica, but I got a strange result. It should be different because the two terms should remain.
...
0
votes
0answers
67 views
Can't create matrix function of symbolic functions and assign values to elements
So I have a problem regarding the symbolic matrix value assignment.
Say I create a matrix function as:
P[t_]:= {{P1[t]}, {P2[t]}, {P3[t]}};
Then I want to assign ...
6
votes
1answer
78 views
unexpected StringCases behaviour inside function module
First, Let use see
a = {"wx", "wy", "wz"};
AssociationThread[Flatten[StringCases[a, "w" ~~ d_ :> d]] -> a]
gives
<...
0
votes
1answer
48 views
Could anyone help me to plot the following function? [closed]
Unfortunately Mathematica is not able to run the following program
area[d_]:=Pi*d^2/4
Q=80/1000
v[d_]:=Q/area[d]
[Nu]=10^-6
Reynolds[d_]:=v[d]*d/[Nu]
[Epsilon]=0.04/1000
CW[[Lambda],d]:=1/Sqrt[[Lambda]...
2
votes
1answer
70 views
How to make an interactive solver function?
I am working on creating a function that takes in any physics equation as a string and converts it to an equation that I will then paste into an interactive interface as asked here: How to make an ...
0
votes
0answers
20 views
(Laplace Coefficents) Integral function definition
TLDR: need help defining two functions involving integrals in the form of "Laplace Coefficents".
My intention is to define functions that involve Laplace Coefficents. In particular, if
$$b_{...
0
votes
0answers
29 views
Suppressing tensor indices and function labels of a function
I am trying to do some GR calculations, and want to write a code which shows the expressions symbolically using compact indices, rather than write all the quantities in detail. More precisely, ...
0
votes
2answers
52 views
How to use NSolve while specifying the range of one variable
I have an equation that uses three variables that I have defined as follows: b[l_, m_, lt_] := 0.025 * (((1 - m)*l)^(-1/2))*((1 - m)*lt) - 5.
After this definition, ...
3
votes
1answer
94 views
What's the meaning of Sign function applied to matrices with MatrixFunction?
I have noticed that Sign function can be very well applied to matrices using MatrixFunction. It even works on some zero divisors,...
0
votes
0answers
72 views
Multivariate Pade approximant
Does Mathematica generate multivariate or just two-variate Pade approximant? If so, what is the generating command?
0
votes
0answers
44 views
0
votes
0answers
38 views
2
votes
0answers
36 views
Can't match custom head in function signature [closed]
I have written a financial charting function which has the following signature;
...
0
votes
1answer
31 views
Setting rules for Gamma functions
I have some expressions involving lots of Gamma functions. Now the arguments of the functions sometime go to zero, in which case I want to use the factorial instead of the Gamma function (since it ...
11
votes
1answer
707 views
How to make a haunting ghost?
How to make a harmless ghost (one that looks like a flying bed sheet)?
One can always make a Ghost Curve.
Or one can define define a clever wiggly function with a random fluctuation.
My initial guess ...
3
votes
1answer
39 views
What is the precedence or order of operation for multiple functions applied to a dataset?
This is from the Wolfram Language book section 45 on the planets dataset.
This works:
...
2
votes
1answer
62 views
How to manipulate functions?
This is probably a simple question, I have matrix a , and I construct b from a by adding a variable to the first column. b is a function of variable d, and now I need to do mathematical calculation on ...
-3
votes
1answer
50 views
Maximize function problem [closed]
I don't understand why I'm getting no solution with the Maximize function in this case:
while it returns the right result when I impose $y\leq0.999$ (or, equivalently, $x\leq0.999$):
1
vote
1answer
50 views
How i can add an element of one sublist to other?
I have list.
st = {{1, 2, 3}, {}, {}}
It is nessesary to add the first element of any sublist to start of other sublist. In a quick way. Example: from 1 to 2 ...
0
votes
2answers
78 views
NMaximize - global maximum fail - How to?
Problem :
Let x,y,z be non-negative real number whose sum is 1.
Find maximum of 0.2x + 0.2y + x^2*z + y*z^2
What I did first was reducing variable.
...
0
votes
1answer
54 views
Asymptotic bode plot [closed]
Is it possible to plot an asymptotic bode plot. I am interested in verifying my straight line bode plot approximations done by hand by using mathematica but the bodeplot function generates the curved ...
0
votes
0answers
43 views
How to define the normalized spacing?
I want to write the formula for normalized spacing in Mathematica and I want to use it in rest of the problem. To write the formula $D=(n-i+1)(x_{(i)}-x_{(i-1)})$ I wrote the following function.
...
0
votes
0answers
63 views
Ising Model 1D /Thermodynamics properties
I want to plot the thermodynamics properties of the Ising model like free energy, entropy, magnetization..etc., when h=0 ( no external field ) and when h= finite values
For the energy as function of ...
2
votes
1answer
108 views
How to expand a function as a linear combination of other functions?
I would like to be able to expand certain functions as linear combinations of other specified functions when I know that the original function can be represented in such a way e.g. we know that $\sin^{...
1
vote
0answers
63 views
Does Mathematica assume real variables in this case?
When we have a function like $f(x) = x^2-1$ and we expand it in a power series about some $x = x_0$, does Mathematica automatically assume that $x$ is real valued?
